Since the 1960s, the birth control pill has been available as a form of contraception only usable by women. Men have had two mainstream forms of contraception, condoms and vasectomies.

Researchers at the University of Minnesota have developed a third option, a birth control pill for men. They recently discovered a usable substance, called ouabain, which is the centerpiece of their research.

This gap has drawn attention to the question of why birth control pills have not been available to men until now. “The obvious reason is that men don’t get pregnant,” said Elaine Tyler May, an American studies professor at the University of Minnesota. The ways in which birth control pills affect women could not be replicated on men, until now.

Ouabain is a toxic plant extract found in eastern Africa. In the past, groups within Kenya, Tanzania, Rwanda, Ethiopia and Somalia would apply the toxin to their arrowheads to make the weapons lethal. Injected ouabain has the ability to stop the heart from beating.

The researchers have altered the ouabain molecule so that instead of latching onto heart tissue, it latches onto sperm cells. Mature sperm cells contain an “a4 transporter,” which is what the altered ouabain molecule searches for within the human body. Once the ouabain molecule latches on, it reduces the sperm’s mobility. The general idea is that if the sperm cannot reach the egg, then pregnancy cannot occur.

“The University of Minnesota is clearly a leader in the development of new and innovative methods of contraception,” said Daniel S. Johnston, chief of the National Institute of Child Health and Human Development’s contraception research branch, to the StarTribune. “I think that the drug targets their recent paper is focused on is extremely promising, and the project is one of the most advanced in our portfolio.”

Because ouabain’s effect is temporary and only affects existing sperm cells, the contraceptive effect should be reversible. Once a male stops using the pill, new sperm cells should no longer be affected by the ouabain molecules, and users should retain their reproductive capabilities.

“I’d want to know just how temporary the effects of the pill are before I consider taking it” said first-year Bryan Powell.

Trials for the male birth control pill are expected to be completed in five years. If successful, there will be a balance shift of options of birth control between males and females. The result being that men will share the same amount of responsibility as women when it comes to contraception.

“An agent like this would be helpful to couples to better plan their families when they want to have children, and it would not be all on the woman,” said Gunda Georg, head of the Department of Medical Chemistry at the University of Minnesota’s College of Pharmacy.

“If half the population suddenly had access to a form of contraception that did not exist before, it’d be respirable to expect rates of unwanted pregnancies to go down,” said sophomore Jessie Proctor.

Since the responsibility of birth control has medical, social and financial implications, spreading the responsibility of this common form of contraception could be a significant step closer to gender equality.